H ere are a couple very effective tools to help you make easy work of aligning the Timing and Rear Main Covers on yourLS1-2-3-6-7-9-LQ4-LQ9-4.8L-5.3L-6.0L -6.2L L92 LS4 L99 LSA. These precision CNC machined Billet PVC Plastic AlignIt Tools get the covers centered perfectly with the crank.